Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b33ce635c9dafdd…

MALICIOUS

PDF

11.4 KB
MD5: 6c4bb2772c559b86f00363a53b2cad53 SHA-1: db5394ef7ddca8e446b367f005de91ac89408915 SHA-256: 2b33ce635c9dafdd9c77c17b7c6519d9cf05e418c2904fd79f58b17d8e31cbb3
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains embedded JavaScript that leverages the CVE-2007-5659 vulnerability, specifically using the Collab.collectEmailInfo method. The JavaScript is heavily obfuscated but appears to be designed to download and execute a secondary payload. The presence of multiple deobfuscated JavaScript files and the ClamAV detection further support its malicious nature. The attack pattern is consistent with exploiting PDF reader vulnerabilities to deliver further malware.

Heuristics 6

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36079 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36079
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
ef8bdac794684ae9cd4eb7091d80e1c5ca478c06c639d72d01626c1f7ce78b6d
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 578 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
27a984c8d7761d364f3a547473c1ab6c0b96ca85613f0fd21bdd03829f8d98ee
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 11938 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
60bdaf4b01fbc8b4286379ee08987206c93ca75ecfe48ef81feec89f1451c022
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 4912 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).